The legislation requires juries rather than judges to decide if the facts of a case warrant a sentence of 50 years without parole.

Wednesday's 40-0 Senate came one day after the House approved the measure 122-0.

Kansas legislators revised the so-called "Hard 50" law during a special session prompted by a U.S. Supreme Court ruling in a Virginia case. The high court ruled that giving judges the sole authority to determine whether to impose a mandatory minimum sentence was unconstitutional.

Kansas adopted the "Hard 50" in 1999, replacing a mandatory 40-year sentence that had been in place since 1990.